HEPATOBLASTOMA - REPORT OF A CASE WITH CYTOLOGIC, HISTOLOGIC AND ULTRASTRUCTURAL FINDINGS

Hepatoblastoma, although rare, is the most common primary malignant ne oplasm of the liver in children. In this paper we describe a case of h epatoblastoma with unusual cytologic features and present the histolog ic, immunocytochemical and ultrastructural features of this neoplasm. A 7-month-old girl presented with a large hepatic mass and metastatic nodules in both lungs. Intraoperative biopsy revealed a hepatoblastoma . Aspiration biopsy yielded a highly cellular aspirate with cords of p leomorphic cells embedded in a mucoid matrix. Histologic sections show ed a diffusely infiltrative neoplasm composed of Sheets and cords of h ighly pleomorphic cells. The neoplastic cells stained strongly positiv e for cytokeratin CAM 5.2 and AE1 and focally positive for alpha-fetop rotein, ferritin, carcinoembryonic antigen and vimentin. Ultrastructur ally, the neoplastic cells had abundant intercellular junctions and in tracytoplasmic aggregates of intermediate filaments. A mucoid matrix, to our knowledge, has not been reported as a finding on aspiration bio psy. This patient presented with pulmonary metastases, and thus we thi nk the mucoid matrix may be a marker of a move aggressive variant of h epatoblastoma. This case illustrates additional cytologic features of hepatoblastoma and the usefulness of aspiration biopsy in the rapid di agnosis of this rare tumor.